1. Field of the Invention
This invention relates to an image processing system which is adapted to electronically interactive-edit images such as characters, designs, and binary images to process and image-record the same as a block copy for printing, further relates to a sampling method for data which is improved in performance by sampling image data printing (density data) in a shorter time and reducing the time required for post-processing. Further, this invention relates to an image generating apparatus in the image processing system which outputs, by layouting, character images formed by code data and bit map images formed by compressed data or non-compressed data.
2. Description of the Prior Art
It is necessary to handle high quality images in a printing field, and it is necessary to process a great amount of image data at a high speed in order to handle the high quality images. It has been heretofore desirable to provide an image processing system for typographers who require high quality printed matter in which characters, designs or the like are consolidated as a whole for editing the same. Notwithstanding, such system has not been proposed but is less capable and practical in use even if it is available.
Particularly, among others, a desk top publishing art has been gradually realized in a manner of description such as a post script but is still less capable and efficient of an image art. Systems for the typographers have been of course, available but is insufficient in handling (input, display, storage, processing, edition, and output and the like) data in bulk and at a high speed. This is because that the characters and images to be synthetically processed are subjected to various approaches by a description language, and a central processing unit (CPU: software) to thus exhibit a poor performance. In the case of outputting only code data for manufacturing a block copy for printing, it is necessary to convert the code data to bit map data for each characters and further to in advance develop it to the bit map data every some rasters. In the case of outputting only the bit map data, the whole or a part of the output image is stored at a temporary buffer and then transferred to an output unit. However, in order to reduce the capacity of the above buffer, the output unit awaits during the time when the output image is stored at the buffer.
However, the apparatus described above cannot simultaneously output the layouted characters and pictures and has a defect that it needs much time to realize if the apparatus in advance layouts the character bit map in the buffer which outputs the bit map. Alternatively, the apparatus outputs the characters and the picture on the separate paper or photographic film, respectively, and an operator patches on the paper or the photographic film. Under these cituations, it takes much time due to the repetition works such as exposure or printing, and photosensitive materials intermediately produced are wasted.
FIG. 1 is a flow chart showing a typical manufacturing process of a conventional print plate for printing, which comprises steps of inputting code data (Step S40) prepared by a word processor and the like, checking a PPC output after a code conversion (Step S41) of the code as prepared and a composing editing (Step S42), and outputting characters from a computer aided photocomposer (hereinafter referred to as "photocomposer") (Steps S43 and S44). What is termed the composing editing is meant to refer to arrangement of a row of the characters according to a prescribed rule, more specifically a forbidden processing or the like. In general, the word processor used for an office automation or the like is designed so that full scale characters are disposed in order. In contrast, the art of photocomposing is contemplated to obtain high quality characters each of which is a half of the width of the full scale character. In this connection, it should be noted that the PPC output is a synonym for a laser beam printer (LBP). Generally, the output of the high quality image output unit is a black-and-white sensitized paper or film either of which is silver halide and expensive but functions at a speed lower than the LBP due to high resolving power. In contrast, the LBP is of less resolving power because of an electrophotographic system and is thus inexpensive but acts at a high speed. For this reason, the LBP is sufficient for checking and correcting layouts, characters or the like. The PPC output check is also meant to refer to confirmation of the characters or the like prior to the high quality image output without trial. The original for designs or the like is read out by a monotone scanner such as to output the image as screen dotted (Step S45). Computer aided and manual photocomposer character outputs, a line image, and an illustration and the like as well as such the screen dotted output are manually paste up (Step S50). A galley proof of its synthetic image is obtained to check its content and to correct it if necessary (Step S51 and S52). Then, the manual photocomposer output for paste-up is provided to finally check and correct the image (Step S54 and S55). These steps are followed by operations such as a camera work (Step S60), a page cutting (Step S61), a pinhole opaque (Step S62), and a film photo-composing (Step S63) for plate making. It is noted that disadvantages derived from the high quality image output unit are that the image outputted thereby to silver halide sensitive materials (such as a sensitive paper, a film or the like) is made white but not black or is turned adverse by a minute spot. These modifications and amendments are termed "pinhole amendments".
As seen from the foregoing, the conventional plate making process requires a great deal of operations such as repeated paste-up, photocomposing to involve much labor and time, thus considerably decreasing efficiency. In order to plate-make an output page as shown in (B) FIG. 2, it is necessary to store data of images #1-#4 and non-image portion (white or black) in output order as shown (C) in FIG. 2. Since the data of the non-image portion is also stored in a memory as described above, it is impossible to handle the high quality image and enormous capacity is required for the memory. In this connection, it has been described that the non-image portion has only the information on areas.